The invention relates to a component for a knitting system, for example knitting machine needle, a selection element, a coupling component, a transfer component, a holding-down part, a sinker, or a similar loop-forming component. In particular, the invention relates to a system component that executes a controlled movement relative to a cam assembly. The cam assembly is provided with a cam curve, along which glides an extension that projects away from the system component, called a butt, such that the system component moves inside a guide, corresponding to the shape of the cam curve. In particular, the invention relates to a system component for which the cam assembly and the bed, which holds the system component, move primarily or exclusively counter to each other in one direction, such as it the case mostly and primarily for circular knitting machines.
During the operation of a circular knitting machine, the butt glides along the cam curve of the cam and gradually wears down in dependence on such influencing factors as lubrication, contamination, hours of operation, machine speed, thread tension and the like. This is particularly true for the two edges of the butt, oriented transverse to the system component and the movement direction of same, which come in direct contact with the cam curve. In particular the edge facing the hook is subject to material erosion caused by wear, which can lead to a change in the effective operating length of the needle and thus to problems with the looping.
Various measures were taken in the past in an attempt to reduce the wear on the butt.
German Patent Document DE 21 57 404 A1 discloses a knitting machine needle having an elongated body with two flat sides and two narrow sides. During the operation, the body of the knitting needle body is positioned inside a guide slot of a needle bed, wherein the width to be measured between the flat sides of the body is considerably less than the slot width of the guide slot. The knitting machine needle has a butt projecting away from its narrow side and is twisted in longitudinal direction, wherein the direction of twisting is selected such that the butt is inclined relative to the movement direction. The section of the body or shank that is located between the butt and the working part of the knitting machine needle forms a torsion spring, which absorbs impacts against the butt by allowing the butt to carry out a springy swinging movement.
This solution requires a large play on the side between the guide slot defined in the needle bed and the knitting machine needle, wherein the width of the guide slot must be assumed to be preset. As a result, this proposal leads to extremely thin needles and correspondingly also to very narrow butts, which makes the hoped-for reduction in wear questionable.
German Patent Document DE 21 10 916 A1 discloses knitting machine needles, having a butt provided with an external part, which can be welded, glued, or soldered to the butt. The external part comes in contact with the cam assembly. The wear is therefore limited to this external part, the gliding surfaces of which can extend considerably past the edges of the butt.
Parts that are fitted onto the butt, however, represent a source of danger when they separate from the butt. In addition, they increase the knitting tool weight.
The same document also discloses butts in FIGS. 15 to 17, which are provided with an angled or bent-over section. This section projects outward from the butt in the manner of an exposed tongue and is bent around a line extending transverse to the longitudinal direction of the needle.
Needles of this type have not proven successful in practical operations.
German Patent Document DE 29 11 195 B1 discloses a knitting machine needle with a butt that is pressed to shape. Depressions are stamped into the butt parallel to the two edges, which are positioned transverse to the needle and serve to drive the needle. During the production, these depressions are used for the displacement of material, so that the adjoining edges can be smoothed. In many applications, these depressions in the butt have turned out to be locations of breakage and, on the whole, have resulted in only a limited improvement of the knitting machine needle.